The present disclosure relates to wireless communications systems, and more particularly to waveguide devices that may be employed in such systems.
By way of example, a waveguide device may be used for uni-directional (transmit or receive) or bi-directional (transmit and receive) of polarized waves. The waveguide device may include a polarizer that converts between polarized (e.g., linearly polarized, circularly polarized, etc.) waves used for transmission and/or reception via a common waveguide and signals associated with basis polarizations of the polarizer in a divided waveguide section. The polarizer may be a passive polarization transducer. A septum polarizer is one such passive polarization transducer that can operate in a bi-directional manner. A septum polarizer includes a septum which forms a boundary between first and second divided waveguides associated with the basis polarizations. Septum polarizers may provide favorable isolation between the divided waveguides and may be used for concurrent transmission and reception of polarized signals.
Septum polarizer performance has become challenged by increases in bandwidth requirements for various applications. For example, in some applications a septum polarizer may be configured to convert the polarization of signals at more than one carrier signal frequency, in which case the operational bandwidth of the septum polarizer may be relatively large. Conventional designs may have relatively sharp performance drop-off at the band edges. Accordingly, such designs may have little margin and thus require very tight manufacturing tolerances in order to operate over the desired frequency band, which may be difficult to maintain and expensive.